Sunday, April 30, 2017

Understanding Ultrasonic Flow Measurement

externally mounted flow meters
Externally mounted (clamp-on) flow meters (Flexim)
Ultrasonic flow meters measure, via sound waves inaudible to humans, the velocity of fluid flowing through a conduit. The conduit can be a recognizable closed piping run, or open channels, flumes, or chutes. The technology is predominantly applied to liquids and gases.

There are three types of ultrasonic flow meters, differentiated by their means of measurement. An open channel flow meter derives liquid depth by computing geometrical distance, combining it with a velocity measurement and known dimensional properties of a flume or other channel. A Doppler shift flow meter reflects ultrasonic energy off sonically reflective materials and measures the frequency shift between emission and reflection to derive a fluid velocity measurement. The contrapropogating transit-time flow meter, more recognizably, the transmission flow meter. The transmission flow meter has two versions: the in-line and the clamp-on. The in-line configuration is intrusive, with flow meter hardware extending into and exposed to the measured media. A clamp-on style ultrasonic flow meter resides on the outside of the pipe, emitting and receiving the ultrasonic pulses through the pipe wall. These process measurement tools, using ultrasound technology, have the ability to measure fluid velocity and calculate volumetric, mass, and totalized flow. The use of ultrasonic flow measurement is prevalent in the oil and gas, nuclear, wastewater, pharmaceutical, and food and beverage industries. It is also employed in energy management systems as a means to measure energy demand.

ultrasonic flowmeterFor intrusive flow meters, sensors are fitted opposite one another and alternate bouncing ultrasonic signals back and forth in the pipe, in an almost tennis-like format. In an elementary explanation, by increasing the number of sensors, engineers are able to decipher flow proportions through calculations of velocity between sensory transmissions; thereby, the flow volume can be computed.

For externally mounted flow meters, a clamp-on device affixes the flow meter measurement elements to the pipe. One special characteristic of clamp-on flow meters is the ability to transmit ultrasonic signals through piping up to four meters in diameter, making them suitable for application in very large systems such as those found in hydroelectric or wastewater installations. The clamp-on arrangement also facilitates addition of a flow measurement point to an existing system without process interruption.

The technology is pervasive in the processing industries, having its particular niche of applications where it excels. Proper installation is a key element in producing reliable and consistent results. Ultrasonic energy flow technology is used for custody transfer of natural gases and petroleum liquids. Custody transfer usually entails following industry, national, and government standards and regulations. Other popular applications include compressed air system monitoring and energy usage metering.

Ultrasonic flow meters, with no moving parts, are comparatively low maintenance and self-diagnosing. Temperature and pressure measurements are needed to calculate mass flow of gases. When measuring liquid mass flow in pipes, it is generally necessary for the pipe cross section to be media filled in order to obtain reliable results.

Whatever your flow measurement challenge, share it with a process measurement specialist. Combine your process knowledge with their product application expertise to develop effective solutions.

Tuesday, April 25, 2017

Campus & District BTU Energy Metering

Campus & District BTU Energy Metering
Saving energy through non-invasive
ultrasonic thermal energy management.
Measuring energy consumption for university campuses, medical centers and building systems is increasingly critical for conservation as well as for saving money. Energy and BTU metering of cooling and heating systems through the use of highly accurate, clamp-on flow metering instruments is taking hold in a wide variety of markets. Sectors include: large and small commercial complexes, industrial, government and university campuses, healthcare, and real estate. BTU measurement is an emerging market and is fast becoming critical for entities to remain cost-efficient and compliant. The document below (courtesy of Flexim) outlines the primary areas where this technology is used and how it is implemented. Anyone who manages or maintains a large commercial, medical, or governmental facility should contact a local expert to discuss the savings and efficiencies delivered with well-designed metering and communication system.

Monday, April 17, 2017

The Meriam MFC5150x Intrinsically Safe HART® Communicator

MFC5150
Meriam MFC5150
Available in ATEX (intrinsically safe) and Non-ATEX models, the Meriam MFC5150 directly reads Device Descriptions without any translations or subscriptions, enabling communication to take place with any registered or unregistered HART® device. This ensures your HART® transmitter will connect, regardless of brand or model.

The MFC5150 is built on the SDC-625 infrastructure and runs Windows CE. With a 1GHz processor and an 4GBMicro SD card, this HART® communicator is ideal for all of your data storage needs.

The 4.3 inch touchscreen provides excellent anti-glare viewing, allowing for comfortable mobile use in darkness or in bright sunlight. All functions are easily navigated via the full QWERTY keyboard and intuitive icons similar to that of a smart phone.

The handheld HART device also features hyperlink menu paths, teachable device specific shortcuts, instant on, multiple languages, help context, video’s and TAB access to panes just like on a computer.



For more information visit Flow-Tech here, or call 410-666-3200 in Maryland or 804-752-3450 in Virginia.

Monday, April 10, 2017

Introduction to Transmitters

Process transmitters
Flow transmitter (FCI)
Transmitters are process control field devices. They receive input from a connected process sensor, then convert the sensor signal to an output signal using a transmission protocol. The output signal is passed to a monitoring, control, or decision device for use in documenting, regulating, or monitoring a process or operation.

In general, transmitters accomplish three steps, including converting the initial signal twice.

The first step is the initial conversion which alters the input signal to make it linear. After an amplification of the converted signal, the second conversion changes the signal into either a standard electrical or pneumatic output signal that can be utilized by receiving instruments and devices. The third and final step is the actual output of the electrical or pneumatic signal to utilization equipment  controllers, PLC, recorder, etc.

Transmitters are available for almost every measured parameter in process control, and often referred to according to the process condition which they measure. Some examples.
  • Pressure transmitters
  • Temperature transmitters
  • Flow transmitters
  • Level transmitters
  • Vibration transmitters
  • Current, voltage & power transmitters
  • PH, conductivity, dissolved gas transmitters, etc. 
Pressure transmitter
Pressure transmitter
(Yokogawa)
Output signals for transmitters, when electrical, often are either voltage (1-5 or 2-10 volts DC) or current (4-20 mA). Power requirements can vary among products, but are often 110/220 VAC or 24 VDC.  Low power consumption by electrical transmitters can permit some units to be loop powered, operating from the voltage applied to the output current loop. These devices are also called two-wire transmitters because only two conductors are connected to the unit. Unlike the two wire system which only needs two wires to power the transmitter and analog signal output, the four-wire system requires four separate conductors, with one pair serving as the power supply to the unit and a separate pair providing the output signal path. Pneumatic transmitters, while still in use, are continuously being supplanted by electrical units that provide adequate levels of safety and functionality in environments previously only served by pneumatic units.

Many transmitters are provided with higher order functions in addition to merely converting an input signal to an output signal. On board displays, keypads, Bluetooth connectivity, and a host of industry standard communication protocols can also be had as an integral part of many process transmitters. Other functions that provide alarm or safety action are more frequently part of the transmitter package, as well.

Wireless transmitters are also available, with some operating from battery power and negating the need for any wired connection at all. Process transmitters have evolved from simple signal conversion devices to higher functioning, efficient, easy to apply and maintain instruments utilized for providing input to process control systems.